1. Field of the Invention
This invention relates to a structure of a photographic camera in which a thrust type film cartridge (a film cartridge in which a roll film is entirely rolled around a spool in a cartridge body to its leading end) is loaded.
2. Description of the Related Art
In conventional photographic cameras, a film cartridge in which a roll film is contained in a cartridge body with its leading end portion projecting outside the cartridge body is used. Recently there has been proposed a photographic camera in which a thrust type film cartridge is used as disclosed, for instance, in Japanese Unexamined Patent Publication No. 6(1994)-110124. A photographic camera of this type will be referred to as "a novel-type photographic camera", hereinbelow.
As shown in FIG. 6, the film cartridge 2 used in the novel-type photographic camera comprises a cartridge body 3 formed of resin molding halves bonded together and a photographic roll film entirely rolled around a spool 6 in the cartridge body 3 to its leading end. A film exit slit 10 is formed in the side surface of the cartridge body 3 and a shutter member 11 is supported for rotation in the film exit slit 10 to open and shut the film exit slit 10. The shutter member 11 extends in parallel to the spool 6 and is provided with a key 12 at its one end portion. The key 12 is exposed outward at one end face of the cartridge body 3 and the shutter member 11 is rotated between an opening position where it opens the film exit slit 10 and a shutting position where it shuts the same by way of an external shutter opening member which is adapted to be engaged with the key 12.
Opposite ends of the spool 6 are exposed outward at opposite end faces of the cartridge body 3 and are provided with keys 14. A drive mechanism on the camera side is brought into engagement with the keys 14 to drive the spool 6 to feed out and rewind the film.
Further, it has been proposed to provide a guide portion 50 for leading the film 8 fed out from the cartridge body 3 to a film feed passage 32 formed between a camera body 30 (film window) and a pressure plate 31 as shown in FIG. 7. The guide portion 50 comprises a film end guide surfaces 51 and 52 which are respectively formed on the camera body 30 and the pressure plate 31. The leading end of the film 8 is brought into abutment against the film end guide surface 51 on the camera body 30 and then led into the film feed passage 32 under the guide of the guide surface 51.
It is desired that the wall thickness of the camera body 30 be as small as possible in order to miniaturize the camera body. In order to reduce the wall thickness of the camera body without reducing the strength, there has been used fiber-reinforced resin containing therein a fiber material such as glass fiber. By using such fiber-reinforced resin, strength of members of the camera body is increased and the wall thickness of the moldings can be reduced, which is advantageous in compactly forming the camera body.
However with the film guide structure described above, there is a fear of the film surface scratching when the film 8 is guided into the film feed passage 32 by the guide portion 50.
That is, as shown in FIGS. 8 and 9, when the film 8 passes the guide portion 50 into the film feed passage 32, the film 8 runs on a corner portion 54 between the guide surface 51 of the guide portion 50 and the surface 53 of the camera body 30 opposed to the pressure plate 31. Further, upper and lower inner rails 30a are formed on the camera body 30 to extend along the film feed direction as shown in FIG. 9 and the film 8 runs waving between the pressure plate 31 and the camera body 30 due to curl of the film 8. Thus the film surface can be scratched by the edges of the inner rails 30a at the corner portion 54 as indicated at A in FIG. 10. That is, emulsion on the film surface can be scraped off along lines A.
Especially when the corner portion 54 is formed of fiber-reinforced resin, the film surface is more apt to be scratched by the fiber material exposed in the surface of the corner portion 54. The emulsion scraped off from the film can adhere to the other part of the film or can enter the cartridge body 3 and adhere to various parts in the cartridge body 3 when the film 8 is rewound, which can cause deterioration in quality of pictures and/or drop-out when writing magnetic information if the emulsion adheres to a magnetic head.
This phenomenon occurs when part of the surface of the camera body to be brought into contact with the film 8 is not smooth or when the fiber material is exposed in such part of the surface. Even if no fiber is exposed in the surface of the camera body as it is molded, the fiber material can come to be exposed when the surface is worn after repeated feed of film.